Conventionally, in restorative treatment of dental caries and broken or chipped teeth caused by dental caries, dental adhesives and dental composite resins are generally used. Such restorative treatment is carried out according to the following procedure. First, caries is excavated to form a cavity, a dental adhesive is applied to the cavity, and then the adhesive thus applied is irradiated with visible light so as to cure the adhesive. Next, a dental composite resin is placed on the cured adhesive layer, and finally, the dental composite resin thus placed is irradiated with visible light so as to cure the resin.
In the above-described restoration method, two materials, i.e., a dental adhesive and a dental composite resin, are used. Recently, self-adhesive dental composite resins having self-adhesive properties have been developed and practically used as materials usable for restorative treatment with fewer steps and without the use of a dental adhesive.
Such a self-adhesive composite resin contains an acid group-containing polymerizable monomer, which is a component conventionally used in a dental adhesive to impart adhesiveness to tooth structures, in addition to components conventionally used in a dental composite resin, such as a crosslinkable polymerizable monomer and a filler, to provide mechanical strength and a polymerization initiator to improve curability (for example, Patent Literatures 1 and 2).
(Meth)acrylates are generally used as such polymerizable monomers. For example, in Patent Literatures 1 and 2, a crosslinkable polymerizable monomer having a hydroxyl group is used to increase bond strength.